Domino Effect
Chain Reaction
The cumulative effect produced when one event sets off a series of similar events. The term is best known as a mechanical effect, and is used as an analogy to a falling row of dominoes, and typically refers to a linked sequence of events where the time between successive events is relatively small.
Origin
President Dwight D. Eisenhower popularized the concept at an April 7, 1954 press conference, describing how if French Indochina fell to communism, neighboring countries would follow "like dominoes." Though Eisenhower used "falling domino principle," journalists Joseph and Stewart Alsop coined "domino effect" in their syndicated column. The metaphor, building on President Truman's earlier ideas, became central to U.S. Cold War foreign policy and justified Vietnam War involvement.